In recent years, the development of new near infrared long wavelength dyes is a hot research trend in the field of dye chemistry. Such materials are widely used in near-infrared fluorescence imaging, photoacoustic imaging, photothermal therapy, photodynamic therapy, near infrared shielding, solar photosensitive cells, and the like. Near infrared dyes in the literature mainly include cyanine dyes, squaraine dyes, BODIPY dyes, phthalocyanine dyes, etc. The absorption wavelength of these small molecule dyes generally located at the blue region of the near infrared band, i.e., between 650 and 800 nm. Some organic small molecule dyes with longer absorption wavelength are often not suitable for practical applications because of poor stability and poor solubility, etc. In recent years, some organic molecules with large conjugated structures have also been found to have absorption in the near infrared region. However, due to the large conjugated structure, difficult synthesis, difficult modification and high tendency to aggregate, etc., of these dyes, they have not been used in practical applications. In order to meet the need of long-wavelength dyes in the fields of biomedical and material, it is very important to develop new parent cores for near-infrared dye.